Re: [PATCH] thunderbolt: Retain host router DP IN resources during suspend

Mika Westerberg
2022-02-18T14:25:43Z

On Fri, Feb 18, 2022 at 07:38:23PM +0530, Sanjay R Mehta wrote:
>
>
> On 2/18/2022 4:43 PM, Mika Westerberg wrote:
> > Hi Sanjay,
> >
> > On Fri, Feb 18, 2022 at 01:11:25AM -0600, Sanjay R Mehta wrote:
> >> From: Sanjay R Mehta <sanju.mehta@amd.com>
> >>
> >> All DP resources are released during suspend and while
> >> resuming back DP IN resource is not available, therefore
> >> unable to find DP pair to re-establish the DP tunnel.
> >
> > It should get plug event for the DP IN adapters once the router comes
> > back from sleep. Is that not happening here?
>
> Yes, plug event is not happening for the DP IN adapter after resume.
>
> The DP In resources are put into tcm->dp_resources list as part of host
> router enumeration. But when it resumes from sleep, there is no plug
> event happening for DP IN, hence DP IN resource will not be in
> tcm->dp_resources list.

Right but if I understand the spec correctly you should get a new
hotplug event for the DP IN adapters once the host router is moved back
to "enumerated" state. This is how Intel hardware works at least (and
this is the understanding I have from the USB4 spec too). Do you see
anything in the log wrt. this when you resume the domain?